Question

How much should be the percentage decrease in pressure (approximately) to increase the volume of a given mass of a gas by $10\%$ at a constant temperature?___

Answer 1

Let 100 units be the volume at pressure = P
New volume = 110 units at new pressure = P'
$(P-\Delta P)\times 110=P\times 100$
$(1-\frac{\Delta P}{P})=\frac{10}{11}$
$\frac{\Delta P}{P}=\frac{1}{11};0.09\Rightarrow 9\%$